Reviews and questions about the entry-level MPC500
By bt2001bt Sun Dec 21, 2014 5:49 am
I've had it for 3 years and I bet it has less than 5 to 10 hours of usage. I haven't touched it in a couple of years. When powered on the display is blank - except all the pixels where the text should be are turned on.

There is a top row of 16 "rectangles" with 8x5 pixels and a bottom row of the same. On the bottom row, initially for 5 seconds only the top 3x5 pixels are turned on, then the remaining 5x5 pixels turn on.

I removed the batteries and tried starting just from the power chord - same results. Holding erase down and turning on doesn't change anything. I've made no changes to the os and have not added any extra ram beyond how it came from the factory.

Any ideas on what is going on? I didn't get much in the way of google searches. Do I just need to try reloading the OS (with a more recent version)? Thanks for any replies ...
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By mithaeon Sun Dec 21, 2014 6:48 am
Sorry to hear that your 500 is acting up. I cannot offer anything too technical as I do not have any in depth experience with regards to its inner workings.

However, there is no harm in doing a thorough inspection of your unit as it has been sitting for some time.

I'd start by first reseating the RAM as well as opening up the case and making sure that all the ribbon cables are seated correctly and nothing is awry as far as connections go.

It might be a good idea to try and load the newer OS (1.31 I believe) onto a CF card and see if the MPC possibly behaves better when started with the install option.

Hopefully some of the more knowledgeable guys can chime in here and offer some tips. Sorry I cannot give you a definitive answer, just some things I would try!
By bt2001bt Mon Dec 22, 2014 12:56 am
Thanks for the response. I removed the case and checked all the obvious stuff without taking all of the pcbs out. I guess that is next.

I can't upgrade the os, it doesn't seem like bootup will get to that point (shift and turn on). I get the same as above - all the pixels are turned on. I turned the contrast a little in both directions, no change ...

I am sure at a loss how this device can get that messed up just sitting in a cabinet for a couple of years.
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By Ill-Green Mon Dec 22, 2014 3:08 pm
Try to reinitialize the machine. I think you hold ERASE and power up at the sametime.

Like Mitheon said, reload the OS, that usually works too.

Also check your cf card and check for bent pins inside the 500's card reader. Thats also a culprit.
By bt2001bt Sat Oct 14, 2017 2:44 pm
Resurrecting my old thread here. I got irritated and frustrated and threw this in a closet for a while, obviously! I pulled it out a few weeks ago and am trying hard to solve.

I still get the 2x16 double row of black dots upon bootup. Contrast works but only serves to darken the dots or make them disappear when turning the contrast screw. The backlight works. I get 4.98 volts on VCC+ on the lcd board - that along with the contrast and backlight working tell me at least some of the output coming from the two chips supplying the control and data to the lcd are working. However, I never get any text on the screen. I suppose a way of putting this is - it would be like one is blind and trying to use an mpc.

I checked continuity of lcd cable and from main board to lcd. I took the mpc completely apart and put together again. I bought a new lcd display and cable from mpcstuff and replaced the original. Same issue.

No bent pins with the CF card reader. A factory default reset does not have any impact. I did notice this time when I have been looking at this that I can hit the pads and hear sounds, play and stop work. As a matter of fact, the best that I can tell - all functionality seems to work as best I can tell - lights go on and off, the mpc does appear to be booting up - except for the lcd display. I cannot tell this for 100% since the display is not correctly working, I am flying blind and it is easy to get "lost" s to where I am at at times.

I do not have extra memory installed, and I thought everything else was soldered in so I am going to relook at the suggestion to reseat the RAM. I don'r see anything offhand on the main board that is suspicious.

I have not attempted an OS update, and do not believe that I ever did. I am nervous without the display, I might end up bricking it although it is close that that anyway.

Thanks for any suggestions.
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By fantomebeats Sat Oct 21, 2017 6:35 pm
I guess you have to buy main PCB and replace it....
other pcbs and stuff sounds work fine, so if I were you, I would replace main PCB
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By Ill-Green Fri Oct 27, 2017 3:16 pm
Bummer man. If I remember correctly, holding Erase and powering up are not the only methods to reset. Holding Shift and then powering up does something too, I forgot sorry. I parted with my 500 in February to fund the Live.

Could be just a dying screen too.
By bt2001bt Sun Nov 05, 2017 8:00 pm
First of all:

Thanks so much ill-Green and fantomebeats for the responses.

I believe I have come to the end of the road on this. I did get a replacement screen and cable - same issue. The only things left are the shift commands as well as maybe trying reloading the os. Not optimistic.

I do believe and agree that it appears to be a main pcb issue. For grins, I removed all other connections and boards, same issue. I touched up some solder joints as well as inspected the main pcb for any obvious solder issues ...

I also put in a 256 memory stick to see if that would make a difference.

Not sure I want to keep putting money into this by buying a new main pcb. I suspose that is an option. Thinking of just buying a used mpc 500 or more preferably a 1000 or maybe a 2000xl. Won't have money until Christmas, so have time to think about it.

I have an s5000 so originally I was more attracted to an mpc for the sequencing.

Any way thanks for your responses.

I did do some looking into troubleshooting the lcd display and the e4m and debug on the 500 but not worth the time and expense, might as well buy a 2nd used mpc as I said above.